System and method for monitoring device engagement

ABSTRACT

An intravenous ultrasound (IVUS) system can include a catheter and a translation mechanism for translating the catheter. Engagement between the catheter and the translation mechanism may be detected, and the translation mechanism can be placed in a connected or disconnected mode, accordingly. When in connected mode, certain IVUS operations may be enabled when compared to disconnected mode, wherein such operations may be disabled. Thus, some embodiments may ensure proper engagement between the catheter and the translation mechanism prior to allowing certain IVUS operations to be carried out.

TECHNICAL FIELD

This disclosure relates to an intravascular ultrasound (IVUS) system anda method of operating the same.

BACKGROUND

IVUS involves one or more ultrasound transducers emitting ultrasoundenergy based on received electrical signals and sending returnelectrical signals based on ultrasound energy reflected by variousintravascular structures. IVUS is often used to generate images. In someinstances, a console with a high-resolution display is able to displayIVUS images in real-time. In this way, IVUS can be used to providein-vivo visualization of the vascular structures and lumens, includingthe coronary artery lumen, coronary artery wall morphology, and devices,such as stents, at or near the surface of the coronary artery wall. IVUSimaging may be used to visualize diseased vessels, including coronaryartery disease. In some instances, the ultrasound transducer(s) canoperate at a relatively high frequency (e.g., 10 MHz-60 MHz, in somepreferred embodiments, 40 MHz-60 MHz) and can be carried near a distalend of an IVUS catheter. Some IVUS systems involve mechanically rotatingthe IVUS catheter for 360-degree visualization.

Many IVUS systems are configured to perform pullback operations, inwhich imaging components of the catheter are translated through thecoronary arteries of a patient while acquiring images. The result is a360-degree image with a longitudinal component. When performing apullback operation, however, it can important that components of theIVUS system are secured properly to assure that the proper componentstranslate relative to others. When components are not secured properly,the pullback operation may not yield the desired results. Moreover, whena pullback operation fails, the IVUS system operator is often leftunaware that a pullback operation is not working until after it has beenperformed, and even then, may not be sure why the pullback operation didnot work appropriately.

SUMMARY

Embodiments discussed in this disclosure can ensure that an IVUScatheter is properly anchored to other IVUS equipment before enablingperformance of certain IVUS operations. Embodiments of the system caninclude a catheter for inserting into the vasculature of a patient, thecatheter comprising a transducer for producing and receiving ultrasoundsignals that can be constructed into an ultrasound image. Some IVUSsystem embodiments may include a translation mechanism that includes ananchor port for anchoring the catheter, and circuitry configured toprovide a first output corresponding to engagement between the catheterand the anchor port of the translation mechanism. The circuitry caninclude a sensor, such as an optical switch, that detects engagementbetween the catheter and the translation mechanism. In some instances,the circuitry can include digital circuitry, and the first output caninclude a digital signal.

Some embodiments can include a controller configured to determine viathe first output if the IVUS catheter is engaged with the anchor port ofthe translation mechanism. The controller can then place the translationmechanism in a connected mode or disconnected mode based on whether ornot the catheter is anchored to the translation mechanism. If thetranslation mechanism is in the connected mode, the controller canenable certain operations of the IVUS system that are otherwisedisallowed if the translation mechanism is in the disconnected mode.Such allowable operations can include imaging operations and accessinginformation stored in memory, which may be located in the catheter. Insome embodiments, the system can include a display configured toindicate if the translation mechanism is in the connected mode.

The translation mechanism of the IVUS system, according to someembodiments, can include a patient interface module (PIM) and a lineartranslation system (LTS). The PIM can engage the catheter and can besecured to the LTS. The LTS can then translate the PIM with the securedcatheter to perform a pullback operation. The transducer can betranslated inside the catheter to acquire a longitudinal image. In someembodiments, pullback can be allowed or disallowed depending on theconnection state between the catheter and the translation mechanism. Theanchor port on the translation mechanism can be located on the LTS,while the PIM may be placed in connected or disconnected mode based uponthe engagement status of the LTS and the catheter.

The details of one or more examples are set forth in the accompanyingdrawings and the description below. Other features, objects, andadvantages will be apparent from the description and drawings, and fromthe claims.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an illustrative embodiment of an IVUS system.

FIG. 2 is a block diagram of an embodiment of the IVUS system.

FIG. 3 is a view of an embodiment of a linear translation systemaccording to certain embodiments of the invention.

FIG. 4 shows the coupling of a catheter, a PIM, and an LTS according tosome embodiments of the invention.

FIG. 5 is a perspective view of the anchor port of the LTS according tocertain embodiments of the invention.

FIG. 6 is a system level block diagram showing an embodiment of an IVUSsystem comprising a controller.

FIG. 7 is a process-flow diagram illustrating operation of an embodimentof the IVUS system.

FIG. 8 is an exemplary block layout of a display used with certainembodiments of the IVUS system.

DETAILED DESCRIPTION

The following detailed description is exemplary in nature and is notintended to limit the scope, applicability, or configuration of theinvention in any way. Rather, the following description provides somepractical illustrations for implementing examples of the presentinvention. Examples of constructions, materials, dimensions, andmanufacturing processes are provided for selected elements, and allother elements employ that which is known to those of ordinary skill inthe field of the invention. Those skilled in the art will recognize thatmany of the noted examples have a variety of suitable alternatives.

FIG. 1 is an illustrative embodiment of an IVUS system 100. The IVUSsystem 100 of FIG. 1 includes a catheter 102 having a proximal end 104and a distal end 106 for inserting into an artery of a patient 144 forimaging. The catheter 102 may be inserted into the patient 144 via thefemoral artery, for example. In FIG. 1, broken lines represent portionsof the catheter 102 inside the patient's 144 body. According to certainembodiments, the catheter 102 can include a transducer 108 at or nearits distal end 106. To perform an imaging function, the transducer 108can emit ultrasound pulses. The ultrasound pulses can then reflect offthe tissue of a patient 144 and can be detected by the transducer 108,which can convert the reflected ultrasound pulses into an electricalsignal for image construction. Accordingly, an integrated ultrasoundgenerator may be included in the IVUS system.

The IVUS system 100 of FIG. 1 also includes a translation mechanism. Asshown, the translation mechanism 119 includes a patient interface module(PIM) 120 and a linear translation system (LTS) 122. The LTS can bemechanically engaged with the catheter 102. The LTS can be configured totranslate the catheter 102 a controlled distance within the patient 144during a pullback or other translation operation. In this embodiment,the PIM 120 of the translation mechanism 119 also acts as an interfacewith the catheter 102.

The IVUS system 100 can include a user interface 140 that can receivecommands by a system user 142 and/or display IVUS data acquired from thecatheter 102 (e.g., as IVUS images). The user interface 140 may includea traditional PC with software configured to communicate with the othercomponents of the IVUS system 100. In some embodiments, the userinterface 140 may include a display configured to display systeminformation and/or IVUS signals from the catheter 102 (e.g., as IVUSimages). In some embodiments, the user interface 140 can include atouchscreen display, which can act to both receive commands from asystem user 142 and display IVUS data from the catheter 102. In someembodiments, the user interface 140 can include an imaging engineconfigured to construct images from the IVUS data provided by thecatheter 102, such as ultrasound signals provided by the transducer 108.In some embodiments, the user interface 140 can include or be incommunication with the ultrasound generator.

FIG. 2 is a block diagram of an IVUS system embodiment. In someembodiments, the IVUS engine 246 (e.g., an imaging engine) can include aprocessor/controller, memory/data storage, a user interface, and adisplay (among other possible components). These components may beintegrated into, for example, a touch screen display and/or a computer.The IVUS engine 246 can generally be in communication with a translationmechanism 248, configured to translate the catheter 202 or a portion ofthe catheter 202. The translation mechanism 248 can, in someembodiments, include its own display and user interface. The translationmechanism 248 and user interface can allow the translation mechanism 248to be used in a manual mode without requiring operating instructionsfrom the IVUS engine 246. In some embodiments, the translation mechanism248 can include a motor that can be used to adjust the position of thetransducer at the distal end of the catheter 202 rotationally and/ortranslationally.

In some embodiments, the translation mechanism 248 can include a lineartranslation system (LTS) 222. The LTS 222 can include the aforementioneddisplay and interface for allowing manual operation of the translationmechanism 248. In some embodiments, the translation mechanism 248 caninclude a patient interface module (PIM) 220. The PIM 220 can include acatheter interface, which can be attachable to the catheter 202. In someembodiments, the PIM 220 can include the aforementioned motor foradjusting the position of the transducer at the distal end of thecatheter 202. According to some embodiments, a translation mechanism 248can include both a PIM 220 and an LTS 222. In such embodiments, the PIM220 and the LTS 222 may be fixedly attached to one another. The PIM 220and LTS 222 may be in communication with one another, and may eachindividually be in communication with the IVUS engine 246.

In some embodiments of the IVUS system, the transducer on the distal endof the catheter 202 can rotate and/or translate. Rotation of thecatheter 202 can be full 360-degree rotation to allow 360-degree imagingof a location such as a patient's artery. In some embodiments, thecatheter can be an array catheter, in which rotation need not benecessary for such 360-degree imaging. Translation of the catheter 202can allow imaging of multiple locations along the artery. Sequentialscans can be performed at multiple translation positions to form anaggregate longitudinal image. In some embodiments, the catheter 202 caninclude a drive cable, which contains an electrical transmission lineand is coupled to the transducer. In some embodiments, the catheter 202can include a sheath defining a lumen within which the transducer andthe drive cable are allowed to move freely. Thus, in some embodiments,the transducer can both translate and rotate within the sheath via thedrive cable without the sheath moving within the artery. This can beadvantageous to avoid excess friction between the catheter and theinterior of a patient's artery as the transducer is moved during imagingor other IVUS operations. For example, while moving inside the sheath,the catheter does not drag along vessels which may have plaques prone torupture.

According to some embodiments of the IVUS system, the catheter 202 caninclude catheter memory 210. Thus, if the catheter 202 is removed fromthe system, the catheter memory 210 can remain with the catheter 202.This way, information that is deemed important to a specific catheter202 can be kept with that particular catheter 202. In certainembodiments, the catheter memory 210 is located on the proximal end ofthe catheter 202. In some embodiments, the catheter memory 210 cancontain information specific to the catheter 202, such as the model ofthe catheter 202. In some embodiments, the catheter memory 210 cancontain information about the particular components within the catheter202, such as information about the transducer. Such transducerinformation can include the frequency response of the transducer, itsdate of assembly, gain, output level, number of times mated to the IVUSsystem, and/or other transducer-specific information. In someembodiments, the catheter memory 210 can store usage informationconcerning the catheter 202 and/or the transducer, such as usage time,date, duration, and/or information regarding the patient in which thecatheter 202 was used. In some instances, storing such information inthe catheter memory 210 can guarantee that this information isassociated with the correct catheter 202, and/or that the IVUS engine246 can detect this information upon catheter 202 engagement or upon theengine 246 requesting such information.

As mentioned, for some IVUS operations, the transducer can be translatedalong a length of an artery. To facilitate such a measurement, someembodiments of the IVUS system include a translation mechanism 248. Thetranslation mechanism 248 can engage the catheter 202 and enable theoperator of the IVUS system to translate the transducer within thecatheter 202 in a specific way. Among various embodiments of the IVUSsystem, the translation mechanism 248 can translate the catheter 202 adesired distance, at a desired speed, or optionally both. Movement ofthe transducer can be initiated from the translation mechanism 248directly and/or from an external controller such as the IVUS engine 246.In the case of an external controller, translation may be performedmanually by a user or may be part of an automated process.

In some embodiments of the IVUS system, the translation mechanism 248can include a PIM 220 and an LTS 222. In some embodiments, the PIM 220can be configured to attach to the proximal end of the catheter 202.This attachment can include both an electrical and a mechanicalattachment. For example, in some embodiments, the PIM 220 can providethe mechanical interface to secure the catheter 202, as well as themechanical energy to rotate the transducer within the catheter 202. Insome embodiments, the PIM 220 can provide the electrical interface thattransmits the signal from the integrated ultrasound generator to thecatheter 202 and receives the return signal. As such, in someembodiments, the PIM 220 can provide the electromechanical interfacebetween the catheter 202 and the IVUS engine 246.

According to some embodiments, the PIM 220 can be configured to mate tothe LTS 222. The LTS 222, while mated with the PIM 220 and catheter 202,can provide longitudinal translation of the transducer. In manyembodiments, the longitudinal translation of the transducer can involvepullback of the catheter imaging core at a controlled rate. The LTS 222can provide calibrated linear translation for acquisition oflongitudinal IVUS data (e.g., for imaging). The LTS 222 may feature adisplay. The display may indicate the linear distance traversed and/orthe translation speed. In some embodiments, the display may includecontrols for starting/stopping translation, setting translation speed,resetting linear distance traversed to zero, switching to manual mode,and so on. In some embodiments, in manual mode, the IVUS system operatorcan freely move the catheter imaging core forward and backward.

FIG. 3 shows an embodiment of an LTS 322 according to certainembodiments of the invention. The LTS 322 can include a display 324 andcontrols 326 for user observation and manipulation of settings on theLTS 322. The LTS 322 can include a cradle 328 that may be configured tomate with a PIM. In some embodiments, the cradle 328 can translate alonga track 330. In some such embodiments, when a catheter is coupled to aPIM, and the PIM is mated with the cradle 328, the LTS 322 can translatea transducer carried by the catheter in a desired manner by translatingthe cradle 328 along the track 330. The cradle 328 of FIG. 3 is shown intwo possible positions—a distal position 334, shown in solid lines, anda proximal position 332, shown in phantom. In many embodiments, the LTS322 can translate the cradle 328 from the distal position 334 to theproximal position 332 in a pullback operation. It should be appreciatedthat in some IVUS operations, the LTS 322 can be configured to translatebetween the distal position 334 and the proximal position 332 in eitherdirection and/or to stop anywhere in between along the track 330.

In some embodiments, because of the translating ability of the LTS,longitudinal translation of an IVUS transducer can be performed manuallyby the IVUS system operator or under motorized control. Motorizedlongitudinal translation can enables the acquisition of calibratedthree-dimensional volume data. This can allow the IVUS engine toaccurately measure distances along the length of the artery underinvestigation, as well as the imaging of multiple regions of interest ina single procedure by advancing or retracting the IVUS assembly withoutmoving the catheter sheath.

FIG. 4 shows an illustrative coupling of a catheter 402, a PIM 420, andan LTS 422 according to some embodiments of the invention. The proximalend of the catheter 402 can include a connector 416 that attaches to thePIM 420. In some embodiments, the connector 416 can secure theconnection between the catheter 402 and the PIM 420 at catheterinterface 418. In some embodiments, the connector 416 can provide anelectrical and mechanical interface to the catheter 402 from the IVUSsystem. The PIM 420 may rest in the cradle 428 of the LTS 422, which cansecure the PIM 420 during translation operations such as pullback. Thecatheter 402 can include an anchor assembly 414. The LTS 422 can includean anchor port 436. In some embodiments, the anchor port 436 can beconfigured to receive the anchor assembly 414 of the catheter 402.

In many instances, when the PIM 420 is secured to the LTS 422, the drivecable 412 of the catheter 402 can be connected to the PIM 420, and theanchor assembly 414 of the catheter 402 can be anchored to the anchorport 436 of the LTS 422. In many such instances, a translation operation(such as a pullback operation) may be performed. A transducer carried bythe drive cable 412 can be positioned within a patient's vessel at alocation distal to an area of interest. The LTS 422 can translate thecradle 428 from a distal position to a proximal position along a track,thereby translating the transducer from its initial location across thearea of interest. While the PIM 420 is translating with the drive cableof the catheter 402 secured, the transducer in the catheter 402translates with it. Thus, longitudinal IVUS measurements may be made bythe transducer, interfacing with the IVUS engine via the PIM 420. Whenthe anchor assembly 414 of the catheter is anchored to the anchor port436 of the LTS 422, the sheath 410 of the catheter 402 can be held inplace while the transducer is translating and optionally rotating withinit. Thus, a pullback operation (or other translation operation) can beperformed while ensuring that the sheath 410 does not slide within thepatient's vasculature.

In some embodiments, it can be important to ensure that the catheter 402is properly engaged to the LTS 422. As noted, in some embodiments, thecatheter 402 can engage the LTS 422 by the anchor assembly 414 of thecatheter 402 being anchored to the anchor port 436 of the LTS 422.Knowing that the catheter is anchored to the LTS suggests that thesystem is in a configuration conducive to performing certainmeasurements. Thus, it can be advantageous to prevent some IVUSoperations if the catheter 402 is not properly anchored to the LTS 422.To do so, some embodiments of the IVUS system include a sensorconfigured to sense the engagement between the catheter 402 and the LTS422. Some such embodiments can sense the anchoring of the anchorassembly 414 of the catheter 402 to the anchor port 436 of the LTS 422.In some embodiments, if the sensor does not sense the engagement betweenthe catheter 402 and the LTS 422, certain operations of the IVUS systemare disabled.

FIG. 5 shows an illustrative anchor port 536 of the LTS 522 according tocertain embodiments of the invention. The anchor port 536 can include anotch 538 in the surface of the LTS 522. A portion of the anchorassembly 514 of the catheter 502 can be inserted into the notch 538. Theanchor assembly 514 can include a center portion 550, a first stoppingportion 552 and a second stopping portion 554. In preferred embodiments,the stopping portions 552, 554 are larger in diameter than the centerportion 550. It should be appreciated that in some embodiments, a singlestopping portion could be used.

In the illustrated embodiment, the center portion 550 of the anchorassembly 514 is received by the notch 538 in the LTS 522. Once received,stopping portions 552, 554 act to prevent the anchor assembly 514 fromtranslating in a direction substantially along the longitudinal axis ofthe anchor assembly 514, which in some embodiments, is the direction ofpullback during operation of the IVUS system. It will be appreciatedthat the configuration of anchor assembly 550 and anchor port 536 inFIG. 5 is merely exemplary, and that many other complementary anchorassembly and anchor port arrangements that function to prevent axialtranslation of the anchor assembly.

The anchor port of FIG. 5 can include a sensor 560 that is configured todetect the presence of the anchor assembly 514 in the anchor port 536.The sensor 560 can be a mechanical switch, a pressure sensor, an opticalswitch, or other suitable sensor. FIG. 5 shows one embodiment. Thesensor 560 can be an optical switch that includes a photo emitter 562and a photo detector 564 arranged on either side of the notch 538. Thephoto emitter 562 can emit electromagnetic radiation 566 toward thephoto detector 564, which detects the radiation 566. However, when theelectromagnetic radiation is blocked from the photo detector 564 by, forexample, the anchor assembly 514, the photo detector 564 no longersenses the radiation 566. Thus, the optical switch arrangement can beused to detect the presence of an object within the notch 538, such asthe anchor assembly 514 of the catheter 502. It should be noted that,while in FIG. 5 the optical switch is shown as being at the near edge ofthe notch 538, the location of the sensor may be substantially in thecenter of the notch 538, or at any other desired location as long as theanchor assembly 514 sufficiently blocks the electromagnetic radiationfrom reaching the photo detector 564 from the photo emitter 562 whenengaged with the anchor port 536. In some configurations, the sensor caninclude a mechanical switch such as a lever such that when the anchorassembly 514 of the catheter 502 is sufficiently inserted into theanchor port 536, it depresses the lever to indicate the engagement ofthe two. The lever may act to open or close a circuit when depressed,for example.

In some embodiments, the sensor 560 of FIG. 5 can be implemented intocircuitry 660 as shown in FIG. 6. FIG. 6 is a system level block diagramshowing such an embodiment of an IVUS system, further comprising acontroller. Some embodiments of the IVUS system can include circuitry660 configured to provide a first output signal 658. The first outputsignal 658 can corresponds to engagement between the catheter 602 andthe translation mechanism. In some embodiments, the engagement mayinclude the anchoring of the anchor assembly of the catheter 602 intothe anchor port of the LTS 622. The circuitry 660 may include a switch(e.g., an optical switch) or other sensor to produce the first output658.

In some embodiments, the circuitry 660 can include digital circuitry.The digital circuitry can provide via the first output 658 a firstsignal or a second signal depending on the engagement status between thecatheter 602 and the translation mechanism (e.g. if the catheter 602 isor is not anchored to the LTS 622). In some embodiments, the circuitry660 can include analog circuitry. In such embodiments, engagementbetween the catheter 602 and the translation mechanism can be determinedby the analog output crossing a threshold value. According to variousembodiments of the invention, crossing a threshold may occur from eitherabove or below the threshold in order to indicate engagement.

The IVUS system 600 of FIG. 6 includes a catheter 602 that is coupled tothe LTS 622. Circuitry 660 can provide a first output 658 to thecontroller 662 depending on the engagement status of the catheter 602and the translation mechanism. In some embodiments, such as the oneshown in FIG. 6, the engagement status can relate to the engagement ofthe catheter 602 and the LTS 622. In some embodiments, the controller662 can measure the first output 658 directly. In some embodiments, anadditional component may measure the first output 658 and signal thecontroller 662.

In some embodiments, the controller 662 can place the translationmechanism or a portion thereof in a connected mode if the IVUS catheter602 is anchored to a portion of the translation mechanism or in adisconnected mode if the IVUS catheter 602 is not. In some embodiments,the controller 662 can be configured to enable the performance of anIVUS operation if the translation mechanism or portion thereof is in theconnected mode but not enable the operation if it is in the disconnectedmode.

In the illustrated embodiment of FIG. 6, the controller 662 can placethe PIM 620 in a connected or disconnected mode based upon whether ornot the catheter 602 is appropriately engaged to the LTS 622, asdetermined via the first signal 658. After determining the engagementstatus, the controller 662 can communicate with the PIM 620, placing itin a connected or disconnected mode based upon the output 658.

In some embodiments, the IVUS system 600 can receive a command toperform an IVUS operation or task via a user interface or some otherinterface for receiving commands. Upon receiving the command, the IVUSsystem 600 can determine whether or not the IVUS catheter 602 isanchored to the LTS 622 and can place the PIM 620 in the connected ordisconnected mode, accordingly. In some embodiments, the IVUS system 600and/or PIM 620 can be in the connected mode or the disconnected modebefore receiving the command to perform an IVUS operation or task. Inmany embodiments, if the PIM 620 is in the connected mode, the IVUS taskcan be carried out as commanded. In many embodiments, if the PIM 620 isin the disconnected mode, the IVUS system 600 can refuse to carry outthe commanded IVUS task.

In some embodiments, the IVUS operation or task that can be enabled ordisabled based on the mode of operation includes at least one of animaging and a memory access operation. In some embodiments, the memoryaccess operation can include accessing information stored in memorycontained in the IVUS catheter 602. The enabled or disabled IVUSoperation may additionally or alternatively include a pullbackoperation, in which the translation mechanism (e.g., the PIM 620 and theLTS 622) causes retraction of an IVUS transducer carried by the IVUScatheter 602 by a given distance, or any such task translating an IVUStransducer in the proximal direction of the IVUS catheter 602.

In some embodiments, the IVUS system 600 can include a display 640. Thedisplay 640 can be configured to indicate if the translation system,including a part thereof such as the PIM 620, is in the connected mode.It should be appreciated that indicating if the translation system, orparticularly the PIM, for example, is in the connected mode can includemany options. For example, some embodiments of the system can display a“not connected” message if proper engagement is not detected. In such anembodiment, the lack of a “not connected” message may constituteindicating that the system is in the connected mode. Some embodiments ofthe invention may be configured to display a “connected” message ifadequate engagement is detected. Not displaying the “connected” messagemay constitute an indication that the translation system is in thedisconnected mode. Other embodiments can display both “connected” and“disconnected” messages for indication to the user. With further regardto FIG. 6, in such embodiments comprising a display 640, the display 640may be in communication with the controller 662 and/or the PIM 620 inorder to display desired information. For example, the controller 662may signal to the display 640 to indicate whether or not the translationmechanism is in the connected mode, while the PIM 620 may send IVUSimaging signals from the catheter 602 to the display 640.

FIG. 7 is a process-flow diagram illustrating operation of an embodimentof the IVUS system. Like other IVUS systems discussed in thisdisclosure, the IVUS system of FIG. 7 can include a PIM, a catheter, andan LTS, each separate from one another. The catheter can be engaged withthe PIM 772. The PIM can be attached to the LTS 774. The catheter can beattached to the LTS 776. In certain embodiments, attachment of thecatheter to the LTS can include anchoring an anchoring assembly of thecatheter to an anchor port of the LTS. As noted, such attachments andconnections can be important in a variety of IVUS operations, such asimaging and/or pullback. In some embodiments, the IVUS system candetermine if appropriate anchoring of the catheter has been detected778. If it is, the system or components of the system can be placed in aconnected mode 780 and, in some embodiments, the user can be alerted 790of the connected mode of operation. This may be done via a displaycomponent of the system as described above and/or via any suitableaudible or visible alert. Upon placing the system or component of thesystem in a connected mode, certain IVUS operations may be enabled 782.The IVUS system may then perform an IVUS task 784, such as a pullbacklongitudinal imaging measurement. Components of the system that can beplaced into a connected mode include the PIM, the LTS, and the catheter,for example. Among various embodiments of the IVUS system, anycombination of these or other components may be placed in connectedmode.

If, on the other hand, it is determined that the catheter is notproperly anchored to the LTS, the IVUS system or component of the IVUSsystem may be placed in a disconnected mode 786. Similarly to theconnected mode discussed above, components or combinations of componentssuch as the PIM, the LTS, and the catheter can be placed in disconnectedmode. In disconnected mode, particular IVUS operations may be disabled788. Disabled IVUS operations may include imaging operations,translation operations, and memory access operations, among others. Insuch a case, the user can be alerted of the disconnected mode ofoperation 790. As noted, this alert may be done via a display componentof the system as described above and/or via any suitable audible orvisible alert. It should be appreciated that, while the processillustrated in FIG. 7 shows the steps in an illustrative sequence, thisparticular sequence does not define operation of all embodiments of theinvention. Various steps may be modified among varying embodiments ofthe invention without sacrificing operability of the IVUS system.

FIG. 8 is an exemplary block layout of a display 840 used with certainembodiments of the IVUS system. In some embodiments, the display 840 candisplay an IVUS image 892. The image may be a real-time image displayedduring IVUS measurements. The image may be a stored image displayed uponrecall from memory. During an imaging operation, the display 840 mayfurther include a selection of image acquisition settings 894. Suchsettings may include zoom and gain settings to adjust while acquiringultrasound images. These settings may be selected and adjusted via theuser interface, which may include a touch screen or an additionalexternal selection tool, such as a keyboard and/or a mouse. In someembodiments, the display 840 may further include connection indications896, indicating to the user of the system which components are connectedand operational. In some embodiments, the connection indications 896 canappear only when particular components are sensed as connected. Forexample, in FIG. 8, “LTS,” “Catheter,” and “PIM” are all shown,indicating each of these elements is sensed by the system. In, addition,the connection indications 896 section can include the indication“Mated,” indicating that the catheter is anchored to a part of thetranslation mechanism, such as the LTS, and that operations requiringsuch engagement are enabled. As discussed, the indication of sufficientengagement of the catheter to the LTS, for example, can be done in avariety of ways, depending on the particular IVUS system, the context,and a variety of other factors.

It should be appreciated that components described with regard toparticular embodiments of the invention may be combined to formadditional embodiments. The techniques described in this disclosure mayalso be embodied in or encoded in a computer-readable medium, such as anon-transitory computer-readable storage medium containing instructions.Instructions embedded or encoded in a computer-readable storage mediummay cause a programmable processor, or other processor, to follow theinstructions prescribed. Computer readable storage media may includerandom access memory (RAM), read only memory (ROM), a hard disk, opticalmedia, or other computer readable media.

Various examples have been described. These and other examples arewithin the scope of the following claims.

The invention claimed is:
 1. A method for operating an intravascularultrasound (IVUS) system that includes circuitry, a translationmechanism comprising a patient interface module (PIM) and a lineartranslation system (LTS), the PIM including a catheter interface and theLTS being configured to translate the PIM between distal and proximalpositions and comprising an anchor port separate from the catheterinterface, and an IVUS catheter having a sheath including an anchorassembly positioned near the proximal end of the sheath, the anchorassembly being configured to engage the anchor port of the LTS, a drivecable positioned within the sheath, the drive cable being coupled to anIVUS transducer at a distal end, and a connector located at the proximalend of the drive cable, the connector being separate from the sheath andconfigured to provide an electrical and mechanical interface between theIVUS catheter and the catheter interface of the translation mechanism,the method comprising: receiving a command to perform an IVUS taskcomprising translating the PIM between a distal position and a proximalposition relative to the anchor port via the LTS in order to cause thedrive cable to move between a distal position and a proximal positionrelative to the sheath; measuring a first output from the circuitrycorresponding to engagement between the anchor assembly of the IVUScatheter and the translation mechanism; determining, via the firstoutput, if the anchor assembly of the IVUS catheter is anchored directlyto the translation mechanism; placing the translation mechanism in aconnected mode if the anchor assembly of the IVUS catheter is anchoredto the translation mechanism or in a disconnected mode if the anchorassembly of the IVUS catheter is not anchored to the translationmechanism; and performing the IVUS task if the translation mechanism isin the connected mode but not if the translation mechanism is in thedisconnected mode.
 2. The method of claim 1, wherein the circuitrycomprises a sensor that detects when the anchor assembly of the IVUScatheter is anchored to the translation mechanism.
 3. The method ofclaim 2, wherein the sensor is an optical switch.
 4. The method of claim1, wherein the IVUS system further comprises a display, and the methodfurther comprises indicating on the display if the translation mechanismis in the connected mode.
 5. The method of claim 1, wherein the IVUStask further comprises performing an imaging function.
 6. The method ofclaim 5, wherein the IVUS task comprises translating an IVUS transducercarried by the IVUS catheter in a proximal direction while performingthe imaging function.
 7. The method of claim 1, wherein the IVUS taskfurther comprises accessing information stored in the IVUS catheter. 8.The method of claim 1, wherein the circuitry comprises digitalcircuitry, and the first output is a digital signal.
 9. An intravascularultrasound (IVUS) system, comprising: an IVUS catheter comprising: aconnector at a proximal end, a sheath having an anchor assemblypositioned near a proximal end of the sheath, the anchor assembly beingseparate from the connector of the IVUS catheter, and a drive cablepositioned within the sheath, the drive cable being coupled to theconnector at a proximal end and an IVUS transducer at a distal end; atranslation mechanism comprising a patient interface module (PIM)including a catheter interface configured to electrically andmechanically interface with the connector of the IVUS catheter and alinear translation system (LTS) including an anchor port separate fromthe catheter interface and configured to receive the anchor assembly ofthe IVUS catheter in order to anchor the anchor assembly of the IVUScatheter to the LTS of the translation mechanism; circuitry configuredto provide a first output corresponding to engagement between the anchorassembly of the IVUS catheter and the anchor port of the translationmechanism; and a controller configured to (i) determine, via the firstoutput, if the anchor assembly of the IVUS catheter is engaged with theanchor port of the translation mechanism, and (ii) place the translationmechanism in a connected mode if the anchor assembly of the IVUScatheter is anchored to the translation mechanism or in a disconnectedmode if the anchor assembly of the IVUS catheter is not anchored to thetranslation mechanism; wherein at least one IVUS operation is enabledwhen the translation mechanism is in the connected mode and is disabledwhen the translation mechanism is in the disconnected mode; and when inconnected mode, the controller is further configured to cause the LTS totranslate the PIM between a distal position and a proximal positionrelative to the anchor port in order to cause the drive cable to movebetween a distal position and a proximal position relative to thesheath.
 10. The IVUS system of claim 9, further comprising a display,the display configured to indicate if the translation mechanism is inthe connected mode.
 11. The IVUS system of claim 9, wherein thecircuitry comprises a sensor that detects if the anchor assembly of theIVUS catheter is engaged with the anchor port of the translationmechanism.
 12. The IVUS system of claim 11, wherein the sensor comprisesan optical switch.
 13. The IVUS system of claim 9, wherein the circuitrycomprises digital circuitry, and the first output is a digital signal.14. The IVUS system of claim 9 wherein the IVUS operation comprises atleast one of an imaging operation and a memory access operation.
 15. TheIVUS system of claim 9, wherein the IVUS operation comprises a pullbackoperation in which the translation mechanism causes retraction of anIVUS transducer carried by the IVUS catheter by a predetermineddistance.
 16. A non-transitory computer-readable medium containingexecutable instructions for enabling operation of an intravascularultrasound (IVUS) system comprising circuitry, a translation mechanismcomprising a patient interface module (PIM) and a linear translationsystem (LTS), the PIM including a catheter interface and the LTS beingconfigured to translate the PIM between distal and proximal positionsand comprising an anchor port separate from the catheter interface, andan IVUS catheter having a sheath including an anchor assembly positionednear the proximal end of the sheath, the anchor assembly beingconfigured to engage the anchor port of the LTS, a drive cablepositioned within the sheath, the drive cable being coupled to an IVUStransducer at a distal end, and a connector located at the proximal endof the drive cable, the connector being separate from the sheath andconfigured to provide an electrical and mechanical interface between theIVUS catheter and the catheter interface of the translation mechanism;the medium comprising instructions for causing a programmable processorto: measure a first output from the circuitry corresponding toengagement between the anchor assembly of the IVUS catheter and thetranslation mechanism; determine, via the first output, if the anchorassembly of the IVUS catheter is anchored to the translation mechanism;enable performance of an IVUS operation comprising translating the PIMbetween a distal position and a proximal position relative to the anchorport via the LTS in order to cause the drive cable to move between adistal position and a proximal position relative to the sheath if theanchor assembly of the IVUS catheter is anchored to the translationmechanism but not if the anchor assembly of the IVUS catheter is notanchored to the translation mechanism; and if performance of the IVUSoperation is enabled, instruct the IVUS system to perform the IVUSoperation.
 17. The computer-readable medium of claim 16, wherein thefirst output is a digital signal.
 18. The computer-readable medium ofclaim 17, wherein the digital signal is provided by a sensor for sensingengagement between the anchor assembly of the IVUS catheter and thetranslation mechanism.
 19. The computer-readable medium of claim 16,further comprising instructions for causing a programmable processor toindicate on a display if the IVUS catheter is anchored to thetranslation mechanism.
 20. The computer-readable medium of claim 16,wherein the IVUS operation comprises an imaging operation.
 21. Thecomputer-readable medium of claim 16, wherein the IVUS operationcomprises accessing memory in the IVUS catheter.
 22. Thecomputer-readable medium of claim 16, wherein the IVUS operationcomprises translation of the translation mechanism.
 23. Thecomputer-readable medium of claim 16, wherein, if performance of theIVUS operation is enabled, the instructing the IVUS system to performthe IVUS operation is performed automatically.